1. Field of the Invention
This invention relates to a foldable stroller, more particularly to a foldable stroller with a backrest frame which can be concurrently folded during a folding operation of the stroller.
2. Description of the Related Art
A conventional foldable stroller includes a main frame with front and rear legs which are provided respectively with two front wheels and two rear wheels, and a seat frame, a backrest frame, and a handle frame mounted pivotally on the main frame so as to be folded to be disposed close to the main frame. In addition, the backrest frame is disposed to be turnable to a desired inclined position relative to the seat frame. However, since the backrest frame is maintained in the position when the stroller is folded, a separate folding operation of the backrest frame is needed, thereby resulting in inconvenience during folding of the stroller.
The object of the present invention is to provide a foldable stroller in which a backrest frame thereof can be concurrently folded during a folding operation of the stroller.
According to this invention, the foldable stroller includes a pair of front legs spaced apart from each other in an axial direction. Each front leg includes a front lower end to carry a front wheel, a front upper end opposite to the front lower end in a transverse direction transverse to the axial direction, and an intermediate portion interposed therebetween. A suspending rod has a front securing end pivotally mounted to the front upper end about a first axis, and a middle support portion extending from the front securing end rearward and downwardly to terminate at a rear holding end which carries a rear wheel. A stump includes a connected end pivotally mounted to the front securing end about a second axis parallel to the first axis, and an upright portion extending from the connected end in the transverse direction and uprightly to terminate at a rest end. Thus, the front leg and the respective stump are turnable about the first and second axes respectively to transform the stroller between a folded position, where the front lower end and the rest end are closer to the middle support portion, and an unfolded position, where the front lower end and the rest end are remote from the middle support portion.
A mounting bar includes an anchoring end connected to the intermediate portion, and a mount portion extending rearward from the anchoring end to terminate at a rearmost end. A linking lever has a fulcrum pivoted to the mounting portion about a third axis parallel to the second axis, a weight end pivoted to the middle support portion, and a coupling joint disposed at the opposite side of the fulcrum. As such, the coupling joint is turned about the third axis to move closer to the rearmost end when the foldable stroller is transformed from the unfolded position to the folded position. The coupling joint includes a pivoted area, upper and lower barrier walls extending in the axial direction and on the opposite sides of the pivoted area in the transverse direction, and a guiding path extending between the upper and lower barrier walls and disposed forwardly of the pivoted area.
A handle rod includes a rider end disposed to rest on the middle support portion when the stroller is in the unfolded position, an anchoring segment extending from the rider end upwardly and pivotally mounted on the pivoted area about a fourth axis which is parallel to the third axis, a lower arm extending from the anchoring segment upwardly, and an upper arm extending from the lower arm and distal to the anchoring segment. A locking coupler is provided with a locking portion, and is movable relative to the lower arm between a locked position, where the locking portion is hindered by the upper barrier wall from moving forward, thereby preventing turning of the upper and lower arms, and a released position, where the locking portion is disengaged from the upper barrier wall, thereby permitting the turning of the upper and lower arms to be closer to the front securing end. An actuator is disposed to actuate the locking coupler to move away from the anchoring segment so as to place the locking coupler in the released position. A biasing member is disposed to bias the locking coupler to move towards the anchoring segment.
A guarding rail includes left and right side rail portions, each having a front end supported by the rest end, and a rear end extending rearwardly from the front end to terminate at a respective one of left and right pivoted ends. Each of the left and right pivoted ends is pivotally connected to the lower arm about a fifth axis parallel to the fourth axis and proximate to the upper arm.
A backrest frame includes a pair of stiles spaced apart from each other in the axial direction and inboard to the handle rod. Each stile includes a lower stile end pivotally mounted to the pivoted area and turnable about the fourth axis, an upper stile end opposite to the lower stile end, and an intermediate stile segment interposed between the upper and lower stile ends.
A holding member has first and second connected ends respectively secured to one of the stump and the guarding rail, and the intermediate stile segment. Thus, when the upper and lower arms are pushed forward and are turned about the fourth axis while the locking couplers are in the released position, downward movement of a respective one of the left and right side rail portions, which arises as a result of pivoting movements of the lower arm and the stump, induces a jerk force to the holding member, thereby bringing the upper stile end to turn about the fourth axis and to fall down together with the upper arm by virtue of gravity.